如何烧开一个动画菜单，该菜单在cursive输入时打开，在光标被移除时关闭？

Question

当我拖动光标时，我可以打开菜单，但如果我向下拉它，我就不知道如何关闭它。我尝试了onmouseou，但它并没有真正起作用，因为当我移动鼠标时，它总是关闭的。css代码中有一些额外的东西

    <div id="mySidenav" class="sidenav">
        <a href="#">123</a>
        <a href="#">123</a>
        <a href="#">123</a>
    </div>
    <span onmouseover="openNav(this)" style="font-size:30px;cursor:pointer" >&#9776;MENÜ</span>

.sidenav {
  height: 100%;
  width: 0;
  position: fixed;
  z-index: 1;
  top: 0;
  left: 0;
  background-color: #111;
  overflow-x: hidden;
  transition: 0.5s;
  padding-top: 60px;
}

.sidenav a {
  padding: 8px 8px 8px 32px;
  text-decoration: none;
  font-size: 25px;
  color: #818181;
  display: block;
  transition: 0.3s;
}

.sidenav a:hover {
  color: #f1f1f1;
}

.sidenav .closebtn {
  position: absolute;
  top: 0;
  right: 25px;
  font-size: 36px;
  margin-left: 50px;
}

function openNav() {

    document.getElementById("mySidenav").style.width = "250px";
  }

  function closeNav() {
    document.getElementById("mySidenav").style.width = "0";
  }

Answer 1

您正在使用错误的事件侦听器。这两个将完成这项工作：

• mouseenter: https://developer.mozilla.org/en-US/docs/Web/API/Element/mouseenter_event
• mouseleave: https://developer.mozilla.org/en-US/docs/Web/API/Element/mouseleave_event

还有-最好在你的js中设置事件监听器，而不是html：

function openNav() {
  document.getElementById("mySidenav").style.width = "250px";
}

function closeNav() {
  document.getElementById("mySidenav").style.width = "0";
}
// Listener set on menu mouse enter
document.getElementById("menu").addEventListener("mouseenter", ()=>{openNav()});

// Listener set on sidenav mouse leave
document.getElementById("mySidenav").addEventListener("mouseleave", ()=>{closeNav()});

只需要给菜单一个id来选择它：

<div id="mySidenav" class="sidenav">
  <a href="#">123</a>
  <a href="#">123</a>
  <a href="#">123</a>
</div>
<span id="menu" style="font-size:30px;cursor:pointer" >&#9776;MENÜ</span>

这里有一个指向工作jsfiddle的链接：https://jsfiddle.net/msq4ogza/4/